Ventilator monitor and alarm devices are used to monitor the presence of pressure in a ventilator circuit and give an alarm when that pressure fails or falls below a preselected minimum. Such monitor devices may be provided with a preset minimum pressure and a preset time delay after which time the alarm will be energized if the minimum pressure is not sensed in the circuit. The monitors may also be provided with means for adjusting the minimum pressure to be sensed with or without an adjustable time delay.
Although such monitor and alarm devices normally operate quite satisfactorily for their intended purpose when they are turned on, unfortunately sometimes a user inadvertently fails to activate the device. It is to the elimination of such a problem that the present invention is directed.